如何在 JavaScript 建構函式中新增屬性、方法？

以下是為 JavaScript 建構函式新增屬性和方法的程式碼 −

範例

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
   body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
   }
   .result {
      font-size: 20px;
      font-weight: 500;
      }
</style>
</head>
<body>
<h1>Add property,method to javaScript constructor</h1>
<div style="color: green;" class="result"></div>
<button class="Btn">CLICK HERE</button>
<h3>Click on the above button to add property, method to constructor</h3>
<script>
   let resEle = document.querySelector(".result");
   function Human(firstName,lastName){
      this.firstName = firstName;
      this.lastName = lastName;
   }  
   let obj = new Human('Rohan','Sharma');
   document.querySelector(".Btn").addEventListener("click", () => {
      Human.prototype.welcome = function(){
         return 'Welcome '+this.firstName + ' ' + this.lastName;
      }
      Human.prototype.age = 22;
      resEle.innerHTML = 'Adding property to constructor : age <br>' + obj.age + '<br>';
      resEle.innerHTML += 'Adding function to constructor : welcome() <br>' +
      obj.welcome() + '<br>';
   });
</script>
</body>
</html>